A 58 year old man has been behaving oddly at home for the last few days and is brought to your ED by the police and ambulance personnel.

He required 5mg of IM midazolam to facilitate his transfer to hospital.

On arrival to your ED he has a GCS of 4/15

Vital Signs:

BP 90/60

PR  115/min

Temp 36

His blood results are:

pH  7.11  (7.36-7.44)

pCO2  16  (35-45  mmHg)

pO2   135  mmHg

HCO3  6  (22-26  mmol/l)

BE  -21  (-2-2)

SaO2  98%

Na  144  (137-145  mmol/l)

K  4.5  (3.4-5.5  mmol/l)

Cl  114  (99-111  mmol/l)

Glu  7.8  (4-6 mmol/l)

Lactate  29  (<2 mmol/l)

Urea  2.7  (3-8  mmol/l)

Creat  130  (<130  umol/l)

Hb  160  g/l

Alcohol  < 0.01%

ketones 1  (<2)

Ca  1.09

Questions:

1. Describe the abnormalities

2. Give a reasonable differential diagnosis

3. What one single test would you ask for to help make a diagnosis?